Different types of light sources are well-known in the art. Point light sources emit light from a small region. E.g. an LED (Light Emitting Diode), a LASER (Light Amplification by Stimulated Emission of Radiation) or a filament can act as a point light source. Linear light sources emit light from a region which has one large dimension. A linear light source could be shaped like a tube with circular, square or other cross section, e.g. a bank of LEDs, a fluorescent tube, a gas discharge tube, an incandescent filament. Surface light sources emit light from a region which has two large dimensions.
A light guide is an object that guides light within it. A light guide may comprise a transparent material of a refractive index larger than the refractive index of a surrounding material, and will guide light by total internal reflection. A light guide may also comprise a reflective cavity, and will guide light by reflection.
A light deflector is an element that deflects light traveling within a light guide. A light deflectormay be a small transparent particle or bubble, which deflects light incident on it by refraction, reflection at the boundary, by diffusion inside the particle, by scattering, or by total internal reflection. Light deflectors may be aspherical particles embedded in a specific orientation with respect to the light guide. Light deflectors may change the wavelength of light. For example a light deflector may contain photoluminescent material. Light deflectors may be irregularities or small white dots or geometric shapes, such as prisms or lenses.